While the spell half of an MDFC might not be super efficient, drawing an MDFC for your turn is about a thousand times more satisfying and productive than drawing a random land is
Because it is easy to get distorted if you line them up with the same sense as cards you normally search for, you want to consider them as a separate category
#8 2002 1st Edition Shining Charizard from Neo Destiny The Neo Era Pokemon cards from 2002 are legendary, and this Neo Destiny Charizard is the perfect example
MTG has lots of land disruption effects, of course, but Quarum Trench Gnomes does it in a totally different way than today's land-hate cards
It can also be reused with cards like Academy Ruins restocking it to your library, recursion from your graveyard, bouncing and then recasting it, or flickering it back onto the battlefield for another round of exiling death triggers